Orthodontic brackets are widely used to align teeth through the application of forces selectively provided by interconnected archwires and accessories. Brackets are typically of metal, ceramic or composite construction and are interconnected to either bands or bonding pads for attachment to teeth.
In edgewise brackets, an archwire passes through a labially opening, horizontal slot defined by one or more pair of opposing tie wings. The archwire is preshaped and sized to provide the desired forces. In each bracket, a tie wing pair includes a gingivally extending tie wing and occlusally extending tie wing. Once placed in the slot of one or more pair of tie wings, an archwire is typically restricted therein by a ligating device such as a steel or elastomeric ligature.
As orthodontic treatment objectives and techniques continue to evolve, numerous corresponding edgewise bracket designs and interconnecting accessories have been proposed. Recently, it has been recognized that it is desirable to reduce frictional engagement between the archwire and bracket surfaces defining the archwire slot to facilitate space closure and bodily tooth movement. Similarly, in many situations, it is now a goal to reduce frictional engagement between the archwire and ligating device employed to restrict the archwire within the slot. Such friction reduction can markedly increase the rate of tooth movement and reduce the duration of the orthodontic treatment.
At the same time, patient comfort and ease-of-use considerations have become increasingly important. Patient comfort has been largely addressed by reducing bracket size to yield smaller and more smoothly contoured brackets. Ease-of-use considerations have stimulated bracket designs which facilitate practitioner's bracket placement/use and accommodate plural modalities. Lingual orthodontic systems and brackets are desirable due to both aesthetic and certain functional desires, and having a lingual self-ligation bracket system is a long sought after objective, especially one with enhanced friction reducing features.
There is a growing segment of the population that desires a lingual based system in order to correct their teeth. Lingual braces are fastened to the insides, or lingual side, of a person's teeth and are thus hidden from view. Like traditional braces, lingual braces use a system of brackets and wires to apply continuous pressure to teeth, encouraging them to gradually shift into alignment. Such lingual based bracket systems have become popular among adults who want an improved smile without having to display to the public a mouthful of metal, typically associated with adolescence, the more conventional and typical period of life when teeth are straightened. The advent of self-ligating brackets opens up opportunities for the relatively recent expansion of lingual based bracket systems and there is a long-felt, but unsolved need for systems that incorporate a cost effective and easy way in which to facilitate lingual based systems.